At 8.45 a.m., Justin started driving from Town X to Town Y which was 380 km away. For the first 150 km, he travelled at an average speed of 100 km/h. He then decreased his speed by 25 km/h and completed the remaining journey.
- Find the total time taken for the whole journey. Express your answer as a mixed number.
- At what time did she reach Town Y?
(a)
Time taken for the first 150 km
= 150 ÷ 100
= 1
50100 = 1
12 h
Speed for the remaining journey
= 100 - 25
= 75 km/h
Remaining distance
= 380 - 150
= 230 km
Time taken for the remaining journey
= 230 ÷ 75
= 3
575= 3
115 h
Total time taken
= 1
12 + 3
115= 1
1530 + 3
230= 4
1730 h
(b)
1 h = 60 min
1730 h =
1730 x 60 = 34 min
4 h 34 min after 8.45 a.m. = 1.19 p.m.
Answer(s): (a) 44
1730 h; (b) 1.19 p.m.